Transparency makes me happy.

With aterm (transparent only to backgrounds, not other windows) and an imagemagick script to shade backgrounds, I get to have pretty much any photo I want as a background, and it doesn't impact my work.

Only exception: astronomical photos with lots of stars. Very hard to resolve a white '.' character.

Shading script is short. Here it is for reference:

  #!/bin/bash
  # should set my background and darken the image for aterm
  # imagemagick documentation here:
  # http://www.imagemagick.org/script/command-line-options.php#fx

  convert $@ -fx 'u/2.0' ~/.shadedbackground.jpg
  fbsetbg -c ~/.shadedbackground.jpg

And, my aterm options:

  aterm -tr -sl 10000 -fg white -bg black

Terminals that permit a dynamic view of obscured windows are also occasionally useful. For example - keeping an eye on small process-monitoring gui while continuing to code.